Apparatus for the treatment of vegetable matter, in particular tobacco



Sept. 3, 1968 EGR] APPARATUS FOR THE TREATMENT OF VEGETABLE MATTER, IN PARTICULAR TOBACCO 2 SheetsSheet 1 Filed July 28. 1966 HQ. I

H 3 I m 7 r z u 6 n M .w w w 2 I l l P p 0 .4. m

Sept. 3, 1968 EGR| 3,399,680

APPARATUS FOR THE TREATMENT OF VEGETABLE MATTER. IN PARTICULAR TOBACCO Filed July 28, 1966 2 Sheetsh 2 United States Patent O 3,399,680 APPARATUS FOR THE TREATMENT OF VEGETABLE MATTER, IN PARTICULAR TOBACCO Laszlo Egri, Basel, Switzerland, assignor to Tamag Basel A.G., Birsfelden, Switzerland, a corporation of Switzerland Filed July 28, 1966, Ser. No. 568,457 Claims priority, application Switzerland, Aug. 2, 1965, 10,842/ 65 14 Claims. (Cl. 131-134) The present invention pertains to an improved apparatus for the treatment of vegetable matter, in particular tobacco, by means of a streaming gaseous medium. The inventive apparatus is of the type comprising a plurality of tower-like cells superimposed on top of one another to provide at least one column, each cell being laterally bounded by cell wall means and having a gas permeable partition member situated within each such cell for subdividing the latter into a charging compartment for the tobacco and a flow compartment for the gaseous medium, the charging compartment of each such cell being arranged above its flow compartment.

Raw tobacco is subjected to a previous treatment before it is processed into the actual smoking article, for instance, pipe tobacco, cigarettes or cigars. This treatment is quite different, depending upon the origin of the tobacco itself and the smoking article to be produced. However, for most practical purposes it can be classified into three main treating techniques, namely, fermentation, mellowing and wetting or moistening.

During fermentation the tobacco must be brought to a certain moisture content and temperature in order to produce certain changes in the compounds contained in the tobacco. In the so-called stack or pile fermentation, primarily employed for cigarette tobacco, the required heat or thermal energy is delivered by exothermic fermentation. Due to the cooling and drying at the marginal region of the stack, it is necessary to re-stack the tobacco a number of times. Such re-stacking requires a considerable expenditure of labor and also the uniformity of the thus obtained material leaves something to be desired. With chamber fermentation employed primarily for neutral tobaccos, especially cigarette tobacco, the tobacco units are washed with conditioned air in closed insulated compartments.

During mellowing the tobacco is permeated by a gaseous medium which removes from such tobacco a portion of its nicotine and ammonia. Finally, during moistening or wetting, the tobacco is treated with a gaseous medium containing water vapor and from which it can remove the required moisture.

In all three types of treatment the adjustment and maintenance of certain moisture and temperature values of the tobacco is important. With some of the known prior art apparatuses a gaseous and/or vapor containing medium is passed through the tobacco in order to mellow and wet it. However, these apparatuses are not suitable for fermentation because it is not possible to economically permeate the large quantities of tobacco which are available and must be immediately processed after harvesting and drying. On the other hand, during moistening the tobacco collapses, bringing about irregular compression of the tobacco charge and resulting in irregular treatment. This compression is always greater in the lower tobacco layer 'due to the inherent weight of the tobacco than in the upper layer.

Most of the installations which were previously employed for the treatment of tobacco by means of gaseous medium operate with relatively high pressure because of the high flow resistance of the charge. As a result, they must be constructed with correspondingly strong and therefore expensive walls, require a great ventilation capacity and use a great amount of energy. An apparatus for the wetting or moistening of tobacco is also known to the art wherein one or more tobacco bales are placed into a chamber or compartment. Thereafter, there is pushed from above into the interior of the bale or bales a tube provided with later-a1 openings. This tube and the chamber are connected via a conduit with a circulation pump mounted externally of the chamber, so that gaseous medium can be sucked through the tobacco bales out of the chamber and removed by means of the tube located in the bales. Such apparatus provides for a relatively irregular flow through the tobacco bales. Owing to the weight of the bales themselves their lower portions are more compressed or compact than the upper portions, which phenomena is made more pronounced if the tobacco in the installation is moistened.

Accordingly, it is a primary object of the present invention to provide an improved apparatus for the treatment of vegetable matter, in particular tobacco, which overcomes the drawbacks of the prior art devices. Another considerable object of this invention is directed to the provision of an improved apparatus which renders it possible to conduct a gaseous medium uniformly through the tobacco.

Still a further significant object of this invention concerns the provision of an improved apparatus for the treatment of tobacco or the like wherein fermentation, mellowing and moistening can be carried out in succession or as individual treatments with a minimum expenditure of time and under optimum conditions, with space requirements and mechanical work being held to a minimum because the tobacco from the time of introduction up to drying remains in the same apparatus.

A further object of the present invention is to provide an improved apparatus which renders it possible to free the tobacco during every treatment with a gaseous medium from certain undesired volatile components, particularly alkali components, without removing to an undesirable degree desired tobacco components, such as aroma components.

Yet a further object of this invention is to provide tobacco treating apparatus which enables utilization of the sensible heat of the tobacco developed during fermentation to be employed for the most part for carrying out the fermentation operation itself.

An ancillary yet equally significant object of the present invention is directed to an improved apparatus of the type described rendering possible an exact control of the dilferent treating operations.

In order to achieve these and still further objects of the invention, which will become more readily apparent as the description proceeds, the inventive apparatus is manifested by the features that the flow compartment of each cell is provided with a conduit for the infeed or outfeed of the gaseous medium, whereas cover means is provided for the uppermost cell and floor means for the lowermost cell of the column. Further, such cover means cooperate with the uppermost cell to provide therebetween an additional fiow compartment, and a further conduit for the gaseous medium communicates with such additional flow compartment.

Examples of gaseous medium suitable for the purposes of the present invention are mixtures of air, water vapor, ammonia, volatile oxidizing agents and the like, as such are employed for tobacco treatment.

Oiher features, objects and advantages of the invention will become apparent by reference to the following detailed description and drawings in which:

FIGURE 1 schematically depicts a cross-section of one cell of the inventive treatment apparatus and providedwith a floor and a cover portion;

FIGURE 2 schematically depi-cts a column provided H with floor and cover portion and assembled from a number of cells of the type shown in FIGURE 1, further depicting infeed and outfecd conduits for the gaseousmedium; and

FIGURE 3 schematically depicts the circuit diagram of an installation formed from a number of columns of the type shown in FIGURE 2 and having two separate re-circulation systems, each of which contains one circulation pump, an air conditioning unit, at least one analysis device and one of them has a trap or separator.

Turning attention now to the drawings, it should be distinctly understood that only enough of the specific physical structure of the various embodiments of inventive apparatus described herein have been shown to enable one initiated in the art to readily understand the underlying concepts of the invention. Specifically, by referring to FIGURE 1 it will be noted that the therein depicted cell or cabinet C embodies four cell side walls arranged relative to one another so as to provide a substantially square cross-sectional configuration for instance, two of such side walls 11, 12 being visible in cross-section. These side walls 11, 12 etc. are connected at the top and bottom with a flat frame member 13 and 14 respectively. A thin layer of foam material 15 is secured to the upper frame member 13. In the exemplary embodiment, these side walls 11, 12, etc. are externally covered with a thick layer, as generally denoted by reference characters 16, 17, of suitable heat insulating material. On the other hand, such heat insulation can also be provided by having a double wall construction of the side walls, in which case then, appropriate heating elements or the like can be mounted between such side walls. This double wall construction can also be used for conducting the gaseous medium into the flow compartment 22 of the corresponding cell or cabinet C as will be more fully developed shortly.

At the lower region of the cell chamber D surrounded by the aforementioned side walls 11, 12, etc. there is mounted a perforated partition member 18, for instance formed of sheet metal, which is disposed in such a manner that this chamber D is divided into two unequal compartments. The portion or compartment of the chamber D arranged between the perforated partition member or sheet metal plate 18 and the upper frame member 13- serves to receive the tobacco, and hereinafter will be conveniently referred to as the filling or charging compartment 21. The portion or compartment of the cell chamber D located between the perforated partition member 18 and the lower frame member 14 serves to facilitate the uniform throughfiow of the gaseous medium, and hereinafter will be conveniently referred to as the flow compartment 22. One of these side walls of the flow compartment 22, such as side wall 16, is provided with a hole or aperture 16:: in which there is set a tube or pipe 19 equipped with a regulating and shut-off valve 20 of any suitable construction. By way of illustration, the depicted cell C is about 60 centimeters high and possesses a free internal cross-section of about 1 square meter. The perforated sheet metal plates or partition member 18 is situated about 10 centimeters above the lower frame member 14.

The floor 23 has the same cross-sectional configuration as the lower frame member 14 of the cell and is covered at its upper end with suitable layer of foam material 24.

At the top of the cell or cabinet C can be closed or obturated by a cover portion or member E. The latter incorporates a bearing surface 28 which fits onto the frame member 13 of the cell C, flat side walls and an upper closure plate 26, all of which encompass an internal compartment 27. A tube or pipe 29 piercingly extends through one of the side walls, such as the one shown at the right of FIGURE 1, and is provided with a suitable regulating and shut-off valve 30.

FIGURE 2 schematically depicts the manner in which a number of such cells or cabinets C can be stacked on top of one another to form a vertical column, generally designated by reference character F. It will be recognized that the lowermost cell 200 is placed upon the floor member 100 and the intermediate layer of foam material 124 insures for a practically air-tight connection between cell and floor. Above the cell .200 there is situated the cell 300, whereby the contact surface between the upper frame member 200a of the lower cell and the lower frame member 300a of the upper cell 300 is sealed by the layer of foam material 215. In the depicted exemplary embodiment 6 cells or cabinets are stacked upon one another in the described manner, but obviously a greater orless number could be employed. Moreover, the laterally protruding conduits or pipes 219, 319, 419, 519, 619, 719 of each tube neighboring elevationally arranged cells always are directed in the opposite sense. Finally, the depicted column F is sealed at the top by the cover member 800, the conduit or pipe 829 of which is directed in the same manner as would be the conduit of a cell standing in its place. These cells are loosely stacked and only scaled by the layer of foam material provided at the upper frame members. The individual pipes or conduits are detachably connected with both of the stationary conduits 40 and 41, the conduit 41} serving for the infeed of the streaming gaseous medium and the conduit 41 for outfeed or delivery thereof.

The tobacco treating installation schematically depicted in FIGURE 3 contains three columns, 50, 51 and 52, each of which consists of individually stacked cells C, just as was the case with the column F depicted in FIG- URE 2. The pipes or conduits 140, 240 and 340 correspond to the conduit 40 of FIGURE 2 and the pipes or conduits 141, 241 and 341 to the conduit 41 thereof. As will be readily apparent by inspecting the schematic circuit diagram of the installation of FIGURE 3, each aforementioned conduit thereof can be selectively connected, through the agency of associated control valves 142, 242, 342 and 143, 243, 343, to one of two different re-circulatiori systems or cycles. To be able to better distinguish between these two re-circulation systems, one of them is depicted in solid line and the other with dashed lines.

The re-circulation system or cycle shown with solid or full lines contains a circulation pump 60 for the gaseous medium, an air-conditioning installation 61, which can simultaneously be employed for the infeed or outfeed, for mo-istening or drying and for heating or cooling of the gaseous medium. At the output side of this air-conditioning plant or installation 61 there is connected an analyzer which examines the gaseous medium for properties important for the tobacco treatment. Moreover, a pressure line or conduit 62 leads from the output side of the analyzer 65, via the control valves 142, 242, 342 and the conduits 140, 240, 340, to the columns 50, 51, and 52. The return flow from the columns 50, 51 and 52 is conveyed through the conduits 141, 241 and 341 and control valves 143, 243 and 343 and a suction line 63 to an analyzing device 66 and from this location to the separator or absorption means 64 which is directly connected with the circulation pump 60. Y

The re-circulation system depicted in dashed or broken lines in FIGURE 3 likewise contains a circulation pump 70 for the gaseous medium, the delivery capacity of which, however, is considerably greater than that of the circulation pump 60, and an air-conditioning installation or plant 71 which, like the conditioning plant 61, can be employed for the infeed or removal, moistening or drying, heating or cooling of the gaseous medium. At the output side of this air-conditioning installation 71 there is arranged an analysis device 75, similar to the analysis device 65 previously considered. A pressure conduit 72 leads from the analysis device 75 to the control valves 142, 242 and 342 and, from this location, through the same pipes or conduits as previously considered, to the different columns 50, 51 and 52. Once again, the return flow from these columns takes place via the control valves 143, 243 and 343 and a suction conduit 73 directly to the circulation pump 70, in other words the circulation system with the greater delivery capacity does not possess any separator.

There will now be considered the mode of operation of the schematically depicted installation of FIGURE 3 for a complete tobacco treatment consisting of fermentation, mellowing, wetting and drying. Initially, the charging compartment of a larger number of cells or cabinets C are filled with raw tobacco, thereafter the filled cells stacked into a column F, as shown for instance in FIGURE 2, and this column is then connected to two re-circulation systems as shown in FIGURE 3. At first the re-circulation system with the lower delivery capacity, at which there is mounted the separator 64, is switched in. Circulation pump 60 delivers air which is preheated in the airconditioning plant or installation 61, through the pressure conduit 62 and the conduits 140, 240 and 340. The circulation of the hot air internally of the cells C of a column F is schematically represented in FIGURE 2 by broken lines having applied thereto arrow heads.

More precisely, the warm air moves from the conduit 40 through the valves 220, 420, 620 and 830 into the respective flow compartments 222, 422, 622 and the hollow internal compartment of the cover portion 800. The warm air coming from the lowermost flow compartment 222 and the internal compartment 827 of the cover portion 800 only has the possibility of streaming through the neighboring charging compartment 221 and 721 respectively. The warm air arriving in the flow compartments 422, 622 streams through the neighboring charging compartments 321, 421 and 521, 621 respectively. The inlet valves are accordingly regulated such that through each of the valves 420 and 620 approximately twice as much warm air flows as through each of the valves 220 and 830. The hot air, after it has streamed through the charging compartments 221, 321 and 421, 521 and 621, 721, collects in the flow compartments 322, 522 and 722 respectively. From this location it moves through the outlet valves 320, 520 and 720 into the conduit 41, the latter of which is operatively connected with the suction conduit 61 of the recirculation system of FIGURE 3.

The streaming warm air brings about fermentation of the tobacco located in the charging compartments. The beginning, the course and the end of fermentation can be monitored with the aid of the analysis or analyzer device 66 by controlling the air emanating from the columns 50, 51 and 52. In this respect, it is not necessary that fermentation take place in the streaming medium, rather such stream can be cut off after the beginning of fermentation and, only for the purpose of analysis switched in at greater time intervals, or else the quantity of the circulated medium can be strongly throttled. Separator 64 insures that gaseous or vaporous compounds produced during fermentation, and which should not again be brought into contact with the tobacco, are selectively separated from the circulated medium.

As soon as fermentation can be considered to be complete, the composition of the warm air in the air-conditioning installation 61 is changed, a change which can be monitored by the analyzer device 65. The air which is now charged with vapors which render the tobacco mellower is conducted in the same manner as described above, through the individual cells C loaded with tobacco. The mellowing of the tobacco is controlled by analyzing the air leaving the cells by means of the analyzer 66. The separator 64 can also be employed during mellowing to free the circulated gaseous medium selectively from certain components.

After mellowing, the control valves 142, 242, 342 and 143, 243 and 343 are adjusted such that the columns 50,

51 and 52 and the associated cells C are operably connected with the recirculation system having the greater delivery capacity, and depicted with the dashed lines. Now, the circulation pump delivers air, which is moistened by the air-conditioning installation 71 and the moisture content of which is controlled in the analyzer 75, through the pressure conduit 72 into the conduits 140, 240 and 340, and from this location to the cells C containing the tobacco to be treated. After the moistened air has streamed through the tobacco it is returned to the circulation pump 70 via the suction conduit 73, whereby such circulation pump 70 again forces this air into the air-conditioning installation 71.

To complete the treatment the air-conditioning installation 71 is switched over from wetting to drying and excess moisture is removed for such time from the circulating air until the tobacco located in the cells C has attained a predetermined moisture content.

It is to be clearly understood that the heretofore described installation according to the exemplary embodiments given herein can, of course, be modified in a number of different ways depending upon specific requirements. For instance, the individual cells need not possess a square cross-sectional configuration, rather could equally well have a rectangular or circular one, or any other suitable shape. When assembling the cells into columns the position of the conduits or pipes protruding from the cells is dependent upon the location in which the main conduit lines are disposed, that is to say, the conduits of the stacked cells could for instance also all be directed in the same direction or sense. If it is thought advisable or necessary, then an analyzer or a pressure or temperature measuring device could be mounted at the pipe or conduit of each individual cell, whereby the individual stages of the treatment for relatively small quantities of tobacco can be individually controlled. Moreover, a treatment installation such as depicted in FIGURE 3 can incorporate less than or more than three columns, depending upon the capacity of the re-circulation system, the number of cells in each column and the time required for treatment. Furthermore, insofar as the individual columns are concerned it is completely irrelevant whether the direction of flow of the gaseous medium is as shown by the arrows in FIGURE 2 or in the opposite direction thereof. The flow direction is determined by the external re-circulation system.

Naturally, it is sufiicient if only one re-circulation system is provided for the entire installation and such can be open, partially closed or completely closed. The use of a number of re-circulation systems is particularly advantageous if a number of columns can be connected and there is desired a working operation which is as continuous as possible. Then, while one column is being charged with tobacco, at the same time fermentation takes place in another column and in still another one the mellowing operation, and so forth.

With the method practiced according to the teachings of the present invention, the tobacco is preferably distributed in a number of superimposed layers of small height, wherein the individual layers are preferably arranged at a distance from one another and are passed or permeated throughout their entire width practically uniformly by the gaseous medium. The stage for the selective removal or separation of components of the recirculating medium, which either emanate from a previous treatment or from the tobacco itself and as a general rule are alkali reacting volatile components, such as ammonia, nicotine, pyridine and the like, can constitute a conventional absorber for instance. There the gaseous medium is treated with an acidic washing medium such as aqueous sulfuric acid. Advantageously, the re-circulating stream of gaseous medium is conditioned, that is, is regulated to a certain temperature and moisture content. The use of sulphuric acid as absorption agent is preferred, because this acid also renders possible the adjustment of a desired atmospheric moisture in the gaseous medium. The absorption stage can also be used to advantage for removing the carbon dioxide formed primarily during fermentation, and indeed, independent of the removal of alkali components or together with such. In such case, the absorber is preferably charged with an aqueous potassium hydroxide solution.

The fermentation process can be controlled by continuously measuring the value of the pH in the re-circulation system, the content of ammonia, CO nicotine and the like.

The invention will be further better understood by referring to the following example:

EXAMPLE In order to carry out tobacco fermentation it is possible to operate in the following manner: Dried tobacco bushels or loose tobacco leaves, in a layer height of about 40 to 60 centimeters thickness, are placed into the individual cells of a column of the type depicted in FIGURE 2, whereby free air passages are prevented by appropriate packing. The moisture content of the tobacco amounts to about 17% to 22%, the specific value being dependent upon the climate. The charging density amounts to about 200 to 250 kilograms per cubic meter. After connecting the conduits 4t), 41 (FIGURE 2) or 140, 240, 340 and 141, 241 and 341 (FIGURE 3) heating is initiated. In this respect, the air delivered through the conduit 62 for instance, under the action of the ventilator or pump 60 is heated in the air-conditioning installation 61. If the tobacco contains a larger portion of green material, one starts with an approximately 80% to 90% relative humidity of the air by appropriate introduction of water or vapor to the air-conditioning installation 61. The temperature of the re-circulating air is regulated to 40 C. to 50 C. After about 24 hours the temperature of the re-circulating air is increased to 55 C. to 65 C. and the moisture content of the tobacco is brought to 18% to 23%. As already developed, in order to prevent thermal losses in the columns such are advantageously provided with insulating walls or with a double wall construction through which the re-circulating gaseous medium flows. In this manner it is possible to prevent condensation of moisture in the walls of the columns.

As soon as the air flowing out of the tobacco exhibits an alkali or base reaction, the absorption function of the separator or absorber 64 is brought into operation, for instance by charging such apparatus 64 with sulphuric acid until the air is practically neutral. As soon as the tobacco no longer develops any alkali reacting volatile components, fermentation is terminated in that the tobacco is dried in the installation. This can be carried out most simply by shutting off the water supply for the air-conditioning installation, whereby, if necessary, the absorption stage can be called upon for drying the re-circulating gas. Naturally, removal of water can also take place directly in the air-conditioning installation 61, for instance through condensation. Thereafter, the tobacco is brought to a moisture content of 14% to 17% and at the same time cooled to 25 C. to 40 C., by re-circulation of water vapor-containing air through the installation. Also this treatment step can be quickly and simply carried out by appropriate control of the delivery capacity and operation of the air-conditioning unit or installation. Thereafter, the tobacco is removed from the cells of the column or columns and pressed.

While there is shown and described present preferred embodiments of the invention it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims. Accordingly,

What is claimed is:

1. Apparatus for the treatment of vegetable matter, in particular tobacco,by means of a gaseous medium, comprising a plurality of tower-like cells superimposed on top of one another to provide at least one column, each cell being laterally bounded by wall means, a gas permeable partition member situated within each cell for subdividing the latter into a charging compartment for the tobacco and a flow compartment for the gaseous medium, said charging compartment of each cell being arranged above said flow compartment thereof, conduit means for con veying the gaseous medium provided for each flow compartment, cover means for the uppermost cell of said column, floor means for the lowermost cell of said column, said cover means cooperating with said uppermost cell to provide therebetween an additional flow compartment, a conduit for the gaseous medium communicating with said additional flow compartment.

2. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 1, wherein said column is erected such that successive elevationally separated flow compartments are alternatingly employed for the infeed and outfeed of the gaseous medium.

3. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 1, further including heat insulating means provided for said wall means laterally bounding each cell.

4. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 3, wherein said heat insulating means comprises heat insulating material.

5. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 3, wherein said heat insulating means is defined by a double wall construction of said laterally bounding wall means.

6. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 1, further including regulating means operably associated with said conduit means for controlling the flow velocity of the gaseou medium.

7. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 6, said regulating means comprising valve means.

8. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 1, wherein said conduit and said additional flow compartment form portions of said cover means.

9. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 1, further including at least one re-circulation system for the gaseous medium, at least one column connected with said re-circulation system, and feed means for the gaseous medium provided for said re-circulation system.

10. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 9, including a plurality of re-circulation systems, separate feed means provided for each said recirculation system for delivering gaseous medium.

11. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 10, further including separator means provided for at least one of said re-circulation systems.

12. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 10, including means for moistening, drying and/or tempering is provided for at least one of said re-circulation systems. i

13. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 12, including a plurality of said columns, and means for selectively connecting each of said columns to a common recirculation system.

14. Apparatus for the treatment of vegetable matter, in particular tobacco, by means of a gaseous medium as defined in claim 11, wherein there is provided a plurality References Cited UNITED STATES PATENTS 259,553 6/1882 Kissling 131-134 533,339 1/1895 Baker et a1. 34-211 1,523,509

Cobb 34-224 Berka et a1 131143 Touton 131135 X Taggart 11937 Underwood et a1 34-57 Harris 131134 Simonini 131140 Larsson 34-205 1/1925 Braemer 34196 X 10 ALDRICH F. MEDBERY, Primary Examiner. 

1. APPARATUS FOR THE TREATMENT OF VEGETABLE MATTER, IN PARTICULAR TOBACCO, BY MEANS OF A GASEOUS MEDIUM, COMPRISING A PLURALITY OF TOWER-LIKE CELLS SUPERIMPOSED ON TOP OF ONE ANOTHER TO PROVIDE AT LEAST ONE COLUMN, EACH CELL BEING LATERALLY BOUNDED BY WALL MEANS, A GAS PERMEABLE PARTITION MEMBER SITUATED WITHIN EACH CELL FOR SUBDIVIDING THE LATTER INTO A CHARGING COMPARTMENT FOR THE TOBACCO AND A FLOW COMPARTMENT FOR THE GASEOUS MEDIUM, SAID CHARGING COMPARTMENT OF EACH CELL BEING ARRANGED ABOVE SAID FLOW COMPARTMENT THEREOF, CONDUIT MEANS FOR CONVEYING THE GASEOUS MEDIUM PROVIDED FOR EACH FLOW COMPARTMENT, COVER MEANS FOR THE UPPERMOST CELL OF SAID COLUMN, FLOOR MEANS FOR THE LOWERMOST CELL OF SAID COLUMN, SAID COVER MEANS COOPERATING WITH SAID UPPERMOST CELL TO PROVIDE THEREBETWEEN AND ADDITIONAL FLOW COMPARTMENT, A CONDUIT FOR THE GASEOUS MEDIUM COMMUNICATING WITH SAID ADDITIONAL FLOW COMPARTMENT. 